What could possibly go wrong???? This phrase is often jokingly attached to a plan that has a high probability of a bad outcome. But, for design and manufacturing engineers, it’s a question we should be asking ourselves all the time. Particularly when something new is being developed or when a product / process is being changed. When you are manufacturing a large number products at a high rate of speed, something will eventually go wrong. As engineers, it’s our job to identify the risks before they occur and then design strategies to mitigate those risks.
Unfortunately, risk is often completely overlooked when dealing with fasteners. Fasteners may seem like the simplest, most basic component in the assembly, but in reality there are hundreds of ways the overall “fastening system” can fail to meet overall design expectations. Incorrectly designed joints or improperly assembled joints can lead to complete failure of the overall product. A properly designed bolted joint is an extremely reliable and robust system. That’s where a true fastener applications engineer is needed to ensure the joint will do what is needed: keep critical components together for the life of the product.
Here are a couple examples where seemingly minor fastener design decisions could have potentially had a large negative impact on the overall design.
- A high hardness alloy steel fastener was experiencing fatigue failures in life cycle testing. The end user initially asked for a “stronger” fastener. The Field Applications Engineering Team suggested a change to a lower strength fastener tightened to a higher percentage of yield strength. The new design proposed by Field passed the life cycle test with flying colors.
- An industrial customer utilized many zinc electroplated Class 12.9 socket head cap screws in their new design. The Field Applications Engineering Team reviewed the overall design and suggested the Class 12.9 parts be changed to Class 10.9 and Class 8.8 parts whenever possible. The combination of high hardness Class 12.9 parts with zinc electroplate would have made the parts very susceptible to hydrogen embrittlement delayed failures. By suggesting lower hardness fasteners the risk of hydrogen embrittlement failures is dramatically reduced.
Risk comes in many forms. Fastener problems can easily result in many undesirable conditions. Loose joints can lead to end-user perceived poor quality and ultimately failed joints. Inefficient joint designs can erode the product margin and slow down production rates. Production delays and stock outs can result from custom parts being used where standard “off the shelf” parts would also have worked.
When you have a dedicated fastener engineer to partner with, all of these are details that can be identified and mitigated. Field’s fastener engineers have the benefit of reviewing and designing hundreds of fastened joints every year. By partnering with Field, you will have access to a vast array of fastener joint design knowledge and experience while greatly reducing your risk of unexpected problems.